Slide Fill Right

.btn-slide-fill-right {
  position: relative;
  z-index: 0;
  overflow: hidden;
  display: inline-block;
  padding: 12px 26px;
  border: 2px solid #6366f1;
  border-radius: 10px;
  background: transparent;
  color: #6366f1;
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.3s ease;
}
.btn-slide-fill-right::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  border-radius: 8px;
  background: #6366f1;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}
.btn-slide-fill-right:hover {
  color: #ffffff;
}
.btn-slide-fill-right:hover::before {
  transform: scaleX(1);
}